Ring Main Unit

A Ring Main Unit (RMU) is a compact, sealed, and highly reliable type of medium-voltage switchgear (typically 6.6kV to 24kV) designed primarily for the secondary distribution network. Its core function is to provide continuous, uninterrupted power supply by enabling a "ring" or looped network configuration. In this configuration, the RMU allows power to be fed from two separate sources. If a fault occurs on one side, the RMU can quickly isolate the faulty section while maintaining power supply to all downstream loads from the other side, significantly enhancing the system's reliability and availability. RMUs are the preferred solution for underground cable networks in urban areas, industrial estates, infrastructure projects, and renewable energy plants where space is constrained, and supply continuity is critical.